Conditions and loops

if / else, switch, for, while and do … while.

Runs in Zerethon IDE · C (GCC 14) Official C documentation ↗
main.c
#include <stdio.h>

int main(void) {
    for (int n = 1; n <= 4; n++) {
        if (n % 2 == 0) {
            printf("%d even\n", n);
        } else {
            printf("%d odd\n", n);
        }
    }

    char op = '*';
    switch (op) {
    case '+':
        puts("plus");
        break;
    case '*':
        puts("times");
        break;
    default:
        puts("unknown");
    }

    int i = 3;
    while (i > 0) {
        i--;
        if (i == 1) continue;
        printf("i = %d\n", i);
    }
    return 0;
}

Output

1 odd
2 even
3 odd
4 even
times
i = 2
i = 0

Watch out: Without break, a case falls through into the next one. And if (x = 5) assigns instead of comparing — use == (gcc warns with -Wall).

Related topics

Official references